Unidentified gunmen blew up the YMCA library in the Gaza Strip on Friday morning. No one was hurt, but the library was completely destroyed.

Sources in Gaza told The Jerusalem Post the attack was in response to the re-publication of cartoons "ridiculing" the Prophet Muhammad in a number of Danish newspapers last week.

The sources said at least 12 gunmen participated in the assault, the latest in a series of attacks on Christian figures and institutions.

"The attackers kidnapped the two guards before they stormed the building in the Shajaiyeh neighborhood of Gaza City," the sources said. "Then they entered the library, where they detonated a number of explosive charges, causing heavy damage."

One of the guards, Abdel Mu'ti Abu Khoussa, 52, said the attackers also stole computers and other equipment from the offices of the YMCA. Only some of them had masks on their faces, he said.

Issa Saba, secretary-general of the YMCA in the Gaza Strip, said all 8,000 books were destroyed. He said the gunmen also stole a vehicle belonging to the organization.

Hamas policemen who rushed to the scene discovered another bomb in the library that had not exploded.

Although no group claimed responsibility, Fatah officials accused Hamas of being behind the attack. However, Hamas strongly denied responsibility, saying it had ordered an immediate investigation.

Several al-Qaida-affiliated groups in the Gaza Strip have claimed responsibility for a series of attacks on Christian figures and institutions over the past two years. The groups said they would continue their attacks until all 3,000 Christians had left the Gaza Strip.